关于c:C语言实现快速选择

#include <stdio.h>
#include <stdlib.h>

int partition(int* arr, int low, int high) 
{if (low >= high) {return -1;}

    int i = low;
    int j = high;
    int pivot = arr[low];

    while(i < j) {while(i < j && arr[j] >= pivot) {j--;}

        if (i < j) {arr[i++] = arr[j];
        }

        while (i < j && arr[i] < pivot) {i++;}

        if (i < j)
        {arr[j--] = arr[i];
        }
    }

    arr[i] = pivot;

    return i;
}

int kthSmallest(int* arr, int low, int high, int k) 
{while(1) {int position = partition(arr, low, high);

        int index = k - 1;

        if (position == index) {return arr[position];
        } else if (position > k) {high = position - 1;} else {low = position + 1;}
    }
}

int main(int argc, char const *argv[])
{int arr[] = {23, 322, 1, 54, 86, 2, 90, 102, 66, 233, 6, 98};

    int length = sizeof(arr) / sizeof(int);

    int k = 3;

    printf("K-th smallest element is %d\n", kthSmallest(arr, 0, length - 1, k));

    return 0;
}